Wireless terminals may operate in multiple frequency bands in order to provide operations in multiple communications systems. For example, many cellular radiotelephones are now designed for dual-band or triple-band operation in GSM and CDMA modes at nominal frequencies of 850 MHz, 900 MHz, 1800 MHz and/or 1900 MHz. Digital Communications System (DCS) is a digital mobile telephone system that typically operates in a frequency band between 1710 MHz and 1880 MHz. The EGSM band used in much of the world typically operates between 880 MHz and 960 MHz.
Achieving effective performance in all of the above described frequency bands (i.e., “multi-band”) may be difficult. For example, “clamshell” type radiotelephones (radiotelephones that open/close) may present particular design challenges in providing effective multi-band performance. In particular, in the case of a clamshell type radiotelephone, it is known that placing an internal antenna at the bottom of the radiotelephone may allow for relatively small shifts in the performance of the radiotelephone between the open and closed states. However, the bandwidth for such antennas (located at the bottom of these clamshell radiotelephones) may tend to be rather narrow. In contrast, when the antenna is placed near an intermediate portion of the clamshell (e.g., near the hinge) the bandwidth may be improved, but the performance in the open and closed states may vary dramatically. For example, in some cases where a bent monopole type antenna is included in the clamshell radiotelephone, the Voltage Standing Wave Ratio (VSWR) may be about 3:1 in the open state, whereas the VSWR may degrade to about 8:1 when the clamshell radiotelephone is closed. The NEC type 515 radiotelephone is one example of the type of clamshell radiotelephone with the antenna in the bottom of the phone as discussed above.